IF WS2 = ultimate lubricant

[GaleHawkins]

Originally Posted By: edhackett
It was actually a very comprehensive thesis. They looked at each major additive individually and a fully formulated oil. They explained the way WS2 works as an anti-wear, anti-friction additive. They showed why WS2 cannot work in a fully formulated oil.

Abbreviated Cliff's Notes:

The IF-WS2 does not work as miniature ball bearings. It works by bonding to the metal and shearing as does graphite and MoS2. The bonding relies on oxidation of the metal and the WS2. The oxidation inhibitors/anti corrosion additives interfere with the oxidation needed for bonding. ZDDP alone and ZDDP+WS2 show nearly identical wear. The fully formulated oil shows a greater wear increase than what you would expect from looking at the individual effects. I suspect that there is a synergy between the anti-oxidants and ZDDP layer preventing the WS2 from bonding to the metal.

They do not go into the cause of the higher wear seen with WS2. They do mention that the IF-WS2 is larger than the gaps it needs to get into to act directly. My theory is that if the WS2 is prevented from bonding to the metal and acting as an anti-wear/anti-friction additive, it acts as abrasive particles.

I don't know of a way to formulate a practical oil without anti-oxidants or corrosion inhibitors, so I don't think WS2 has any use as a motor oil additive.

They also stress several times that a low coefficient of friction does not always correlate with low wear. That's well known.

Ed


Ed thanks so much for this explanation of WS2 as a motor oil additive and the damage it may cause. We have been reading up on and testing some of the nano tech additive claims. After the tear down of a test engine I could see what the hexagonal boron nitride (Liqui Moly Ceratec in this study) did and did not no do to reduce friction by laying down a ceramic like coating.

Where there was heat and pressure the micron thin coating could be detected like crank and cam bearing surfaces but the piston skirts did not show the same but the cylinder walls did where the rings passed.

Just dumping in additives willy nilly into one's motor oil may not be without risks.

 

[alternety]

ed, I generally agree with what you are saying. I don't really believe that the "ball bearing" mode is the principle mechanism for IF WS2. One point with the IF WS2; it starts out as Bucky Balls, but it shears to fill small surface anomalies. I am assuming that the shear process is in some fashion tied to a bond to the lubricated surface followed by shearing of the "excess" BB construct. I do not recollect seeing an explanation of the exact mechanism anywhere. But it seems like a reasonable explanation. But my guess is that the plating is the primary effect. To paraphrase Wizard of Oz characters; if I only had a lab.

I have seen a reference that indicates that a Graphene like sheet of WS2 may have essentially the same lubricating effect as the IF version. This implies the latter mechanism.

It also makes sense that any IF WS2 floating about that does not participate in surface modification would indeed behave as an abrasive. It is a hard material. And this is where I think the abrasive effect is caused by competition for the surface area. If the WS2 is prevented from bonding, I can see abrasive.

Another interesting area of research would be to evaluate the actual effects of the measured wear. Does it improve the surface in the long term by smoothing surface anomalies while filling depressions? Which would then be categorized as final honing.

I have to spend some time with that paper.

 

[friendly_jacek]

Originally Posted By: edhackett

Abbreviated Cliff's Notes:

The IF-WS2 does not work as miniature ball bearings. It works by bonding to the metal and shearing as does graphite and MoS2. The bonding relies on oxidation of the metal and the WS2. The oxidation inhibitors/anti corrosion additives interfere with the oxidation needed for bonding. ZDDP alone and ZDDP+WS2 show nearly identical wear. The fully formulated oil shows a greater wear increase than what you would expect from looking at the individual effects. I suspect that there is a synergy between the anti-oxidants and ZDDP layer preventing the WS2 from bonding to the metal.

They do not go into the cause of the higher wear seen with WS2. They do mention that the IF-WS2 is larger than the gaps it needs to get into to act directly. My theory is that if the WS2 is prevented from bonding to the metal and acting as an anti-wear/anti-friction additive, it acts as abrasive particles.

I don't know of a way to formulate a practical oil without anti-oxidants or corrosion inhibitors, so I don't think WS2 has any use as a motor oil additive.

They also stress several times that a low coefficient of friction does not always correlate with low wear. That's well known.

Ed


Thanks for the summary. Well put. I think there is still a future for those IF-WS2 nanospheres. At some point, OEM could decide that great decrease in friction is more important than slight increase in wear and go via the unformulated oil + nanospheres route. Maybe someone will discover an additive that will decrease that increased wear associated with IF-WS2. Or maybe new oil types/classes will have to be used (preferably chemically inert if no antioxidants can be used). It will take a paradigm shift to embrace the nanoparticles in lubrication. We are not there yet.

Now, that part about low coefficient of friction does not always correlate with low wear is very contra-intuitive. Would anyone care to explain why?

 

[MolaKule]

Quote:
OK, this was a very informative thread, before all this name calling started.

MolaKule, please apologize or stop posting here if you have nothing constructive to add.


Any comment in any post is subject to peer review and comment.


Science, with testing results, not conjecture, is what wins out, regardless of posturing by an oil dealer.

 

[demarpaint]

Very informative thread I hope it doesn't get locked.

 

[MolaKule]

Quote:
Now, that part about low coefficient of friction does not always correlate with low wear is very contra-intuitive. Would anyone care to explain why?


The paper

http://www.diva-portal.org/smash/get/diva2:565698/FULLTEXT01.pdf

has a very good Stribeck chart and discusses the Stribeck curve on pages 28-29 with respect to the different areas of the lubrication regime.

Different additives function in different regimes of the Stribeck curve.

Quote:
The critical difference between AW/EP additive films and FM films is in their mechanical properties. AW/EP films are semiplastic deposits which are hard to shear off. Thus, under shearing conditions, their coefficient of friction is moderately to high. The exceptions are the organometallic compounds listed above. Friction modification films consist of orderly, close-packed arrays of multimolecular "whiskers," loosely adhering to each other. The outer layers are sheared-off easily, allowing for low coefficient of friction. The phenomena can be described as a deck of plastic coated playing cards lying on the table and sliding off the top card easily.

Conversely, AW/EP films work by protecting the mating metal surfaces from asperities physically gouging the opposite surface. When a hydrodynamic film of oil is ruptured, this layer of AW/EP material protects the mating surfaces from catastrophic failure.

 

[alternety]

There was a little point in a post above about the molecular bonding of WS2 to the base metal. I stated that it is an oxidation process in both base material and WS2. That is the first time I have heard that. It was my impression that the bonding was purely at the atomic forces level of the materials. I suspect that the lubricating properties of the WS2 would be destroyed by getting the compound to become something else through oxidation. I don't believe that WS2 is particularly easy to oxidize either. It works on quite chemically inert materials.

 

[67King]

Originally Posted By: dailydriver
^^^I wonder what Millers adds to their racing oils to counteract/
buffer the supposed added wear? (IF that paper is fully correct in that deduction.)

67King???


I've not read the paper, but it is not what is observed. As stated, reducing the coefficient of friction while increasing wear is, on the surface, counter-intuitive. We have UOA's that show improvements, some of the comments are posted on my website. Improvements gave been seen in BTCC, WRC, F1, IndyCar, etc. The chief engineer for Herta was interviewed at PRI by a show that ran on Velocity where he came right out and said that component life of the crown gear (analogous to ring gear) and pinion increased 190% from the prior best. I've got a letter from him on our website, as well. And given the history of semantics in this thread, for the sake of clarity, a gearbox is an industry term for a transmission or transaxle.

Also, note the time it took to get in the oil. Note the time it took to go from the gear oil to the engine oil. There is obviously more to it than just adding it.

Now there are certain fullerenes that are a bit hydrophillic that will become rather abrasive when wet. I believe it is mainly BN, but don't recall. Not the stuff that is in the Millers.

The mechanism behind this is that the additive fills the low spots. If anyone else here has any background in metallurgy, they know that as you prep a sample for microscopy, you get smaller and smaller grit sizes, and each subsequent step takes much more time than the others, and if you skip sizes, you waste your time. Considering feature sizes are orders of magnitude higher than the additive, it is kind of hard for me to believe that the additive can be abrasive, and certainly since the asperities dwarf the additive, they are going to be more prone to causing issues than the additive. All that said, in addition to filling the low spots, the outer layers of the particles do exfoliate, and form a film. If you know what Graphene is, that is a bit analogous.

As to the additives, and attraction to the metal, etc. ZDDP content was reduced when NT was added. It is higher on the non-NT versions of the race oil. There is interaction with the detergent pack. There is interaction with the ester base stocks. All of these things are polar, and they all fight each other for surface area of the metal. Again, it took 3 years after it was introduced into the gear oils to get it "right" on the engine oils. So you can't just throw this stuff in engine oil and expect an ideal outcome. It is like baking a cake. You have to get the proportions of things right.

Side note, I don't check this thread regularly. I happened to get yet another PM (at least I didn't get a phone call this time around) about being attacked. And it sounded like some mod actually came in and edited it? Regardless, as evidenced by relative post counts, I don't have time to scan message boards developing my [censored] contest skills. What, 3 some-odd posts a day for over a decade? Wow.

Seriously, dude. Grow up. Your profile says you have grandkids. Aren't you old enough to act like a mature adult?

Side note, SAE published another paper about it, for anyone interested in that kind of thing: http://articles.sae.org/12798/

 

[alekhine]

Hi there! First post here so please go easy on me

I think you are correct about industry not being ready for this yet, but concerning the mechanism of these particles (being a chemist) I would rather be inclined to believe the chemistry is more complex in this case. Every compound reacts at some point, but some need more 'convincing' conditions. In a boundary contact the temperature and pressure might be high enough to induce significant changes, regardless of how inert WS2 is said to be. I would recommend a look at this:

Mechanism of Action of WS2 Lubricant Nanoadditives in High-Pressure Contacts
http://link.springer.com/article/10.1007%2Fs11249-013-0195-x

So perhaps it's not that WS2 (fullerene or not) can't be used with something else, it's just that it should be used with something that doesn't interfere with it's normal reaction mechanism.

With this, I would also like to ask a more practical question based on your experience. I am not versed in this field and I am curious how big these particles could realistically be without interfering with the filters. Thank you very much
Vlad

 

[alternety]

The WS2 in the formats being discussed here (mostly IF WS2) are very much smaller than an engine oil filter's pores. As far as the filter is concerned, that particles don't exist.

You can buy non-IF WS2 in many sizes. I suppose you could get it in a particle size that could be stopped by a filter. But nothing that would be recommended for engine use.

 

[alekhine]

Yes, the 2H-WS2 'nanoparticles' on the market actually have a wild size distribution as proven by optical/electronic microscopy. But I assume everything would be fine if you could mechanically decrease their size to one that doesn't interfere with the filters (my opinion is that the relationship between the size of the nanoparticles and that of the surface asperities is less important than the chemistry involved). This is why I was curious about an approximate size you need to reach..
When you said 'nothing that would be recommended for engine use', do you refer to the lack of current dispersion methods available, or is there any other practical reason against it?
(I apologize for shortly changing the subject from IF to 2H WS2)

 

[alternety]

Sorry, I don't understand the 2H-WS2 designation. But I would not put anything other than IF WS2 in my engine. This thread is really quite specific about materials within the range necessary for the purpose.

"nothing that would be recommended for engine use" I mean don't use random chunks of any WS2 in an engine (unless you really feel the need and may be annoyed by your engine). If it makes it through the filter it should cause no harm.

You might want to skim through this thread. This sort of thing has been discussed to death. IF WS2 should maintain a fairly consistent Bucky Ball structures less than 100nm. As the structures decrease in size from adhering and being sheared by mechanical forces, the particles will tend to small clusters of molecules. Or individual molecules. Any of this should be invisible to a normal engine oil filter.

I looked at your link, but I am not going to purchase the document. Looking at the brief abstract, I am not sure what they are going to say. From the abstract: "WS2 nanoadditives react with the metal substrate to generate thick chemical tribofilms". I don't understand the term chemical in that context.

There is no chemical reaction with the IF WS2. Direct atomic forces only. The WS2 can be directly applied to materials with fairly low pressure air sprays. In an engine application after it is assembled, the oil delivers the WS2 while dealing with all the other needs of the engine. I have not found any indications that something actually has to be added to WS2 to make it fulfill it's intended purpose. My guess (and that of some others as well) is that engine oil "compatibility" is more about leaving out conflicting materials (e.g., ZDDP, Molly) than adding things to support the WS2 action.

Essentially a modern oil may have a lot of additives that get in the way of the process. The oil film itself works to keep the plating from happening.

Just an extraneous thought. If I were to rebuild an engine (or get one that had never been run) I would be tempted to pull the spark plugs, put a low speed electric motor on the engine, flush any residual oil and derbies, then put in IF WS2 in a convenient carrier not likely to generate much in the way of a film (like alcohol). Run that at low speed for a while and then get rid of the working fluid. Then put in the oil and follow normal procedures. That should do something toward plating in a much shorter time frame. Then I would use IF WS2 oil. That could reduce "break-in" wear, which may not be desired.

 

[Coronamaker]

alternety the 2H simply designates the WS2 as the platelet type.

Also as far as your thought of using alcohol and IF WS2 to pre-coat, I would suggest instead a clear mineral oil or a maybe a Spectrasyn 4, as alcohol could actually start immediate oxidation of the exposed metals, just a thought. I would not worry about the film that the oil will have as you are only using the oil to get the WS2 to the surfaces to coat. Additionally once the WS2 coats it will hold a layer of oil on the WS2 to further protect the metal surfaces until you actually get the engine fired up and flowing the oil you have filled it up with.

I also would add a slight correction to 67King's last post in this thread about the concern of coating rings, I can state as a fact that this is no problem. In fact when Cadillac brought out their North-Star engine and warranted it for 100K they had initial problems with the rings not lasting. Between the first failures and the re-engineering of the engine, literally hundreds of thousands of rings were spray coated with WS2 to make them last through the warranty period. The WS2 used for this was the spray industry standard 0.5 micron WS2 that is also used to meet the Aerospace and DOD specifications for spray application of WS2 as a dry film lubricant. Additionally many aftermarket rings have been coated with either MoS2 or WS2 going back to the 80’s and earlier, and engine builders for decades have no problems with ring seating or break in due to the coatings.

I am surprised to read the comments from the aforementioned paper, which I have not read fully yet, speculating wear from the WS2. Rockwell Hardness of this material is a fraction of that of steel, and lower than that of aluminum, but then again the Rockwell of water is pretty low and look what it can do if it is coursing through the countryside. But then again, the paper references 5% WS2 by weight which if I calculate correctly is an obscene amount of WS2. I would welcome any correction if I made a Friday mental mistake. My math is below.

1 Gallon of 10-30 oil is roughly 7.3 pounds. Divided by four quarts, that makes 1 quart of said oil approximately 1.825 pounds. Five percent of that would be 1.825 * .05 = .09125 pound or 41.39 grams/Qt of oil. I must be making the same mistake over and over here because this is an absolutely ridiculous amount of WS2 in any form to put into oil. Unless the goal is to turn oil into grease! Even if the Gallon was only 5 pounds it would work out to around 28 grams/Qt, still a ridiculously high amount of WS2. That (.09125 Lb) is like 17,000+ square inches of coverage per quart.

Given that the goal of using a product like WS2 regardless of form is to cover the lubrication surfaces. This actually requires planning to coat all of the oil bearing surfaces of the engine, gearbox, etc. because the WS2 will coat it all eventually, and then you would want to have a very small amount excess to recoat trouble spots if needed. Given that every gram will cover over 400 square inches, it is really not that much WS2 required to do the job. And as ASTM Timken testing has shown that while WS2 provides considerable protection over base oil, the difference in the wear protection between 1.775 grams/Qt and 10 grams/Qt of 0.5 micron WS2 in Shell Rotella T is marginal, the question would be how fast 10 grams per quart will coat versus 2 grams per quart, and also how much is too much? So say you split the difference, treating a 6 quart oil system with 5 grams per quart would yield approximately 12.400 square inches of coverage. That is less than 1% by weight, again provided Friday mental defect has not yet set in.

I only added all this coverage info to further show why I question the thought behind a 5% by weight ratio in testing.

 

[alternety]

Thanks Coronamaker. I was just winging it. My thought was for something with minimal film buildup between parts. Did not think about corrosion. It was just a mind exercise. I have zero interest in rebuilding engines. I have enough things to worry about.

I have some of the Apnano IF WS2 additive. This is already diluted in the mineral oil carrier. They recommend 25ml/L. I have seen quite low percentages, but I don't remember and I don't seem to have saved that info. You may want to check out the Apnano site, they may have the info there. I did find a saved paper and oddly enough it explained 2H. Anyway, here is a bit if text from that paper that I think people here would find interesting.

Text:

It was concluded that impregnation of IF nanoparticles provides
the regime of quasi-hydrodynamic lubrication over
the widest range of loads in comparison to the reference

sample and the sample impregnated with 2H–WS2 particles.
Fe–Ni samples were found to exhibit the highest wear resistance
and provide the widest range of quasi-hydrodynamic
lubrication in comparison to the bronze and iron powdered
composites. The effect of IF on the lubrication regime is
explained on the basis of a third-body model. It is expected
that the sliding/rolling of the IF nanoparticles in the boundary
of the first-bodies and in between the wear particles
(third-body) facilitate the shear of the lubrication film and
thus provide a quasi-hydrodynamic regime of friction. It is
suggested that the quasi-spherical shape of the IF nanoparticles
facilitates their forced impregnation into the porous
matrix and allows their slow release from the pores onto
the contact surfaces.

Source: Friction and wear of powdered composites impregnated
with WS2 inorganic fullerene-like nanoparticles
L. Rapoport a,∗, V. Leshchinsky a, M. Lvovskya, O. Nepomnyashchy a,
Yu Volovik a, R. Tenne b
a Department of Science, Holon Academic Institute of Technology, P.O. Box 305, Holon 58102, Israel
b Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel

 

[alternety]

A reminder. If you want to buy some IF WS2 in a bit of mineral oil,
go here:
www.theoilhub.com/NanoLub

I though at one point they had dropped the product, but they did not. They are however showing a picture of the up to date package from Apnano. Mine came in what appeared to maybe be a container filled from a bulk container. Definitely not a container I saw on the manufacturer's site.

 

[PhillipM]

FWIW, whilst it's off topic a little, to clear up the little spat.

Anybody that actually works, races or develops/designs 'shocks and struts' will call them dampers, because technically the shock absorber is the spring, and the strut is just a casing with some bearings either end...the bit that does the damping, is a damper...I think the use of 'dampen' is an americanism that seems to have been adopted too (probably why people over there keep calling them dampeners instead of dampers) - 67King is right, originally that term only meant 'to wet something', the correct term for applying damping to a part always used to be simply 'damp' - as in "We need to damp the movement", etc.

Here endeth the damper nonclementure lesson.

 

[alternety]

A bit of feedback. I put the Millers Oils IF WS2 oil in a 2013 CR-V. It is my wife's car and she has kept a mileage log from day one. I believe the OEM break-in oil had been in long enough and most initial engine wear-in had occurred (my opinion, no fact). I put in 5W30 instead of the suggested 0W20. So there could have been some impact from that.

Net results. She made some note of the predominant driving conditions (local or highway). With her use it is usually one or the other over one or two tanks. The mpg has increases about 2 mpg under both types of driving.

Not a real scientific test; but indicative. YMMV.

 

[dailydriver]

Their 0W-30 (or 0W-20) Racing might have been even better, but it may have a slightly lower TBN than their 'street' line up, so possibly not as good for extended drains.

I believe the VIs in the same grade are very close between the racing and street labelled oils.

 

[alternety]

I agree. But they were not available when I made my purchase. Rather annoying actually. I still have a significant amount to use up. The problem with being an early adopter. It is the WS2 I am after.

 

[alternety]

Actually my last post is not true. My fingers were faster than my brain. I Just did not want the racing additive package.

Next quest. I need some of the real lube guys to suggest a grease I can use to mix in some IF WS2 concentrate.

I have concentrate in a bit of mineral oil. I have an application where I want to replace the grease recommended my a manufacturer with a WS2 alternative. Please do not start a semi-thread of "the manufacturer knows best" . The recommended material is LPS anti-seize Part No. #04110 with heavy MoS2 content. The parts are in fast motion, it can be cold, gets fairly hot, and things slide and bang into each other at high energies. The grease is necessary to prevent galling and other impact generated surface deterioration.

What I need is a good quality non-hardening non-runny grease, thick enough to stay in place but not generate a huge amount of drag. Good temp range (0F - a couple of hundred}, and no components that will attempt to attach themselves to the substrate (e.g., MoS2, ZDDP, etc.) and might slow the attachment of the WS2. The WS2 concentrate is in a mineral oil base, which may limit the alternatives.

Come on lube pros - I have to believe you have some great possibilities.